2) It still won't compile without extensions added, so it's not nonsense.
Besides, the headers use a lot of things like re-define of defines (without #undef first). Regardless if it ignores this or not, it's not allowed. If extensions are disabled, you get compile errors.
2>d:\program\microsoft sdks\windows\v6.0a\include\specstrings.h(171) : error C2008: '$' : unexpected in macro definitionCode:#define __$adt_prop(adt,prop)